The effect of winter fodder beet or kale allocation on behaviour and blood metabolite status of non-lactating dairy cows

Abstract

Fodder beet (FB) was at first rapidly adopted by farmers, however, there is uncertainty around the impact of feeding high rates of FB on metabolic diseases and cow behaviour. This study aimed to establish if there was an effect of crop type and feed allocation on blood metabolites and behaviour of dairy cows. In winter 2017, 328 mixed-aged pregnant non-lactating Friesian x Jersey cows were allocated to feeding treatments of either FB or kale, offered at two allocation rates: “target” (to achieve 0.5 BCS gain) or “high” (ad libitum allocation), supplemented with pasture baleage. Blood metabolites were monitored for 20 animals per treatment, 15 of those animals per treatment had an activity sensor fitted for 8 days in late July. Cows fed FB had higher plasma magnesium and lower sodium, phosphate, total protein and urea levels than cows fed kale. The FB cows spent less time lying (9.4 vs 11.1 h/d), walked more (2113 vs 1737 steps/day), had fewer lying bouts per day (6.1 vs 9.3 bouts/day), but had longer bout duration (102 vs 81 min) than kale cows. These results indicate differences between winter crops in susceptibility to metabolic diseases and grazing activity which require further investigation.